What goes around comes around especially when it comes to the sun. Space weather experts predict a moderate G2 geomagnetic storm to erupt late tomorrow (Oct. 24th) afternoon and continue past midnight. The blast of high-speed particles from the sun marks at least the second go-round of a big coronal hole that served up several nights of northern lights in late September. Since the sun takes about four weeks to spin around once (on average), the persistent hole has returned, and it appears once again to be fully armed. Sometimes holes can persist for months, with the chance for auroras popping up about once every 28 days.

Coronal holes are large areas in the sun’s corona or atmosphere that aren’t under magnetic lockdown. Here, the sun’s magnetic field lines unfurl into outer space and carry away hordes of particles, moving at high speed, into the solar system. Earth’s in the bullseye, so keep an eye open for northern lights the next few nights with the best night being Tuesday. A moderate storm usually brings the aurora south from Canada to the northern and mid-section of the U.S. We’ll just have to wait and see.

To find a place near your city with dark skies to the north, check out this Light Pollution Map. It’s coupled with Google Maps and color-coded, so you can better pinpoint dark skies. Don’t worry about darkness to the south. North’s what you’re looking for. Good luck!

If skies are clear tonight at your place, watch for the moon and Saturn about an hour after sunset at dusk low in the southwestern sky. Saturn shines just 7° to the left or east of the moon. They’ll be a little closer tomorrow evening with Saturn to the right of the moon.